Add tests for class and static methods

__tests__/core/SubscribingEventEmitter.test.ts

@@ -8,11 +8,31 @@ class Subscriber {
    */
   public events = {
     function: 0,
+    start: 0,
+    static: 0,
   };
 
+  public static staticEvents = {
+    static: 0,
+  };
+
+  onstart() {
+    // this this will throw if "this" is not resolved to current class
+    this.events["start"]++;
+  }
+
+  static staticMethod() {
+    Subscriber.staticEvents["static"]++;
+  }
+
   getSubscribedEvents() {
     return {
+      // inline callback
       function: () => this.events["function"]++,
+      // pointer to class method
+      start: this.onstart,
+      // using static method
+      static: Subscriber.staticMethod,
     };
   }
 }
@@ -34,9 +54,13 @@ describe("utils", () => {
       const worker = new Worker();
       const subscriber = new Subscriber();
       worker.addSubscriber(subscriber);
+      worker.emit("start");
       worker.emit("function");
+      worker.emit("static");
 
+      expect(subscriber.events["start"]).toBe(1);
       expect(subscriber.events["function"]).toBe(1);
+      expect(Subscriber.staticEvents["static"]).toBe(1);
     });
   });
 });